System of mining



Sept. 19, s. M. CASSIDY ETAI.

SYSTEM OF MINING Filed March 4. 1942 EQQ EEDD@ QQ lll UQ 7 nl! .Iglu/5mm I! n. a Umm@ @D EM lmmmll T lEA-l ET/m wmmimmm@ ELVIS.. 1 m n n r` n "Twm iim M .u

f E LVILII Il HUH@ Patented Sept. 19, 1.944

Samuel Cassidy and kGeorge Rigg, Y Y

Uniontown, Pa.

Aappneiufm March 4, 1942, serial N. 433,270

' 4 claims, (o1: 26g-'1) Our invention relates to the art of mining and particularly to improvements in the system of mining coal known as the room and pillar system. The purposeof our rinvention is toincrease the operating efficiency of mining machin-v ery now being used in coal mines. However, our invention may be used to great advantage in coal mines not employingV mining machinery exten`y sively.

In the'mining of coal, a cut orkerf is rst made along a working-*face of the body of' coal `to be removed. This cut is vmade at' the top, bottom, or sides of the working face and is done by a large machine known as a cutter operated by two men. :The cutter is then removed "and a'separate crew of workers drill holes above or below the kerf into which explosive is placed to shoot down the coal. After the coal is shot down another crew of workers load the coal into cars. In modern mining methods this loading is usually done by large mechanical loaders, scrapers, conveyors, or shakingY conveyors. Following the loading and removal of the coal, separate additional crews erect timber -to support the Aroof of the room whichwas formerly supported by the coal and lay track for the cutting and load ing machines and the cars which are used for hauling the coalout of the mine. lf` conveyorsv are used, the crews erectextensions Von to the COnVeyOI'S.

' As stated above, these operations, particularly the cutting and loadingv ofthe coal, aredone by' large machines which are difcult to move and' which represen-t a considerablev capital investment. In systems of mining which havev hereto-v the machinery is idle, so far as'the actual mining' of coal is concerned, for considerable periods of time. Likewise,'the crews which operate the machines are not continuously employed in the mining of. coal. .Y

VWe have invented a systemof mining by which these disadvantages have been overcome. In our system of` mining, a large number of `working faces are concentrated within a relatively small space so that the coal mining machinery'can be quickly moved from one working face `to another. The machines are thus used for the actual mining of coal during a large proportion of the time they are in the mine. VThe crews in charge of the machines are likewise continuously Vemployedin actual mining operations.

` In-the accompanying drawing we haveshow'n a d iagrammaticplan View of 'aj'fbody of'coal in which a system of Ymining embodying our invention is employed. As shown inthegdrawing; omV system comprisesv the driving of several entries 12' to form main headings. In the-draw`ing we have shown4 the main headings as having five entries although any number of entriesmay beYused-so long as there is proper provision for haulageV of the coal and ventilation. 'I'he entries V2 are connected with each other by cross entries? whichA are cut when the entries 2 are being driven into the body of; the .coal to be'min'ed.v The crossen-V tries Y3 are closedjby stoppings 4 -to prevent short-r circuiting of the owof air through 'the entries for ventilationpurposes. From' the main headings, room entries 5 are cutinto'a panel l of the body of coal for the full depth thereof. As shown, the room entries are cut intermediate the sides of the panel.` A suliicient number of irroom entriesA should Abe driven so that there is adequate provision for haulage and ventilation. As was donev with the main headings, we have illustrated ve room entries. Y

In the drawing we have shown a diagrammatic*V plan Vview of amine after operations in accordance with-our'system havefproceeded to a certain extent. rThe entries Shave been completed and rooms or cross entries Vli jhave-been cut to forma row of pillarsl l extending'in'a line across the entries and ofs-uch length as is determined by the requirements of efficient ventilation and removal of the coal. TheY row of pillars extend-sV the full depth of the roomsronv eachside of the room entries. n

The row of pillars lis not mined Abut isleft standing forl reasons which "will hereafterbe,

stated.

As shown in theV drawing'rooms Sareturnedy off of the room entries'5 `onboth'sides thereof' at an angleless than 90". Y The resulting` pillars are then mined, beginning with the row'neztv ofthe pillars proceeds, unsupported, ,caves in asf to row 'I'. As the robbing the mine roof, being shown by the stippled area in the drawing.

The rows'fof pillars which vhavebeen formed are mined in accordance Vwith `a ,systemV which will now be described. 'The drawingv shows the moved by mining on the retreat;l

as having a lift lljin which` ing'down and loading takes 'place at workingv faces in each lift.

The rows 8,?9 and |-o thisv inclined from the room entries toward the head-s J' ings with respect to the rows of pillars.

While mining proceeds at the line of robbing, additional rooms are cut by extending the rooms 5 as indicated in dotted lines at the points I2 in the drawing. It will be noted that these additional rooms will form additional rows of pillars generally parallel to the rows 9 and Ill. VThe additional rooms arekcut at such a rate that as pillar-s-areremoverdl at the line of robbing, additional pillars will be available for mining. Thus, in the drawing, the row I is shown as being ready for mining and is actually started before row 9 is removed. While the last pillarsin row 9. are beingminedthe pillars in row II) assist in the support of the roof so that less timber is required. The rooms are also cut at such a rate thatronly a few rows of pillars are being formed in back of the line of robbing. 'I'his leaves a solid block of coal in back of the line which assists in the support ofthe roof. The panel I is thus minedin accordance with our system until the coal has been removed back to the barrier pillar ingv the main headings.

The first roweof Apillars 'I formed. at the end I3 which is left tovsupport the entries 2 formof'the room entries isallowed to stand so as toV form ableeder entry I4 to draw off gases collecting in the caved in roof or gob 8. Also, a row Yof pillars at one side vof the panel are allowed to remain as mining proceedsso as to form a second bleeder entry running parallel to the room entries.-l In the drawing we have shown a row of pillars I5 which will form a bleeder entry IIS` similar to the bleeder entry I'I which was formed. on the opposite side of thelroom entries 5 by the mining of the panel of coal adjacent to the rpanel I. The purpose ofthe bleeder entries `II and I'l is to assist in removinggases formed in thefgobf. The entries 5 are connected by short cross entries AI8 cut during the driving ofthe room entries. 'Ihe cross entries I8 as well as the rooms 6 all have the usual stop-- pings lor doors whichv are designed to prevent the Yshort-circuiting of ,air which flows through the mine 'for the purpose of ventilation. The flow of air through our system of mining is indicated by arrows'in the drawing.

,l While the panel I is being mined as described above, another set of room entries I9 can be driven intca panel of Ycoal adjacent to the panel I. These entries can be cut at sucha rate that they will have reached the lfull depth of the panel of coal in which they are driven at the timeV the mining has lbeen completed back to the barrier I3 in the panel I.` This second panel will then be ready forthe room and pillar work which has been described above.

,By having afplurali'ty of working faces concentrated in a relatively small area, we greatly reduce the time which-has heretofore been lost in'moving the coal mining machinery from one working face to the other. `Moreover, the machinery, the crews, the track and wiring system used for extracting the pillars are the same as used for cutting the rooms back of the pillar line. The same crews and equipment do both the extracting and development work. The tonnage rate is therefore greatly increased.

While our method of min-ing greatly reduces the time lost in moving machinery from one working position to another, this is only one of theV many advantages Varising from its use. Thus a very important advantage arises from the fact that as soon as the room entries and first cross-entries or rooms are completed, robbing of vuntil the entire panel has been completed. In

room and pillar methods of mining heretofore used only one or two places are started at rst. The number of places is gradually increased theA line of robbing being at a substantial angle to the advance entries, but it has required a period Aof weeks or'months before the full panel width Yis being robbed. Likewise the number of placs has decreased as the mining of a section neared completion.

Another advantage of our system resides in the fact that the roof is supported by rows of pillars :close to the robbing line and by a solid block of coal behind these pillars. The danger ofthe roof collapsing is thereby decreased.

' Thedevelopmentl Work or opening of the room entries, is kept at a Large blocks of coal are left which is a-great advantage in pillar Work. The development work is concentrated so that high tonnage rates are obtained while it proceeds as well as on the subsequent room and pillar operations.

The fact that the working faces are all connected to one central entry, greatly assists in 4the mine.

the changing of mine cars behind the loading machine. Likewise, it is easier for'the "swing or frelay motor to pick up empty and loaded cars where they are left.

. Our system of miningrequires less rock dusting and less time todo the actual rock dusting needed than .in mining systems heretofore used. Since the working faces are concentrated in a smaller area, the amounts of wiring for electric power, pipe lines for drainage, track installation and maintenance, and timbering necessary to carry on the mining operations are all materially re duced. Our system makes possible a simpler system of ventilation, requiring fewer doors for controlling the circulation of air and gases through It also facilitates supervision and thereby promotes increased safety.

Because of these many advantages, our system of mining is not limited to coal mines using mechanical cutters, loaders, etc., but may be protably used in mines using anymining method such as;.hand mining, hand or mechanical methods using track, rubber tired equipment, or Scrapers and conveyors instead of track.

While we have described a present preferred embodiment of our invention, it is to be distinctly understood that it may be otherwise variously embodied and practiced within the scope of the following claims: Y

We claim:

1. In a method of'rnining a body of coal, the steps comprising driving a set of headings into the body, turning a set of room entries laterally from the headings into an intermediate portion of a panel on one side of theheadings and advancing said entries through the panel, turningrooms off of both sides of the entries at the end thereof remote from the headings at angles less than 90 thereby leaving rows of pillars extending from both sides of the entries at the end of the panel remote from the headings, similarly turning additional rooms off of the entires leaving rows of pillars substantially parallel to the rst-mentioned row but nearer the headings than the latter, robbing pillars on one side of the entries substantially along a, line passing through pillars' in a plurality of said rows, simultaneously robbing pillars on the other side of the entry along a line Vto said entries, adjacent the end of the panel remote from the headings, thereby leaving spaced rows of pillars extending on both sides of said entries at said angles thereto, robbing said pillars in retreat ,across the entirev width of the panel simultaneously, commencing at the end of the panel remote from said headings, by establishing working places simultaneously in pillars lying in a plurality of adjacent rows, and maintaining the line of robbing substantially normal to said entries.

3. In a method of miningcoal, the steps including driving a set of headings through a body of coal to be mined, turning a set of room entries off of said headings substantially centrally of the panel lying on one side of said headings, driving said entries through substantially the full depth of the panel, turning rooms off of both sides of said entriesat angles of substantially less than to said entries, adjacent the` end of the panel remote from the headings, thereby leaving spaced rows of pillars extending on both sides of said entries at said angles thereto, robbing said pillars in retreat across the entire width of the panel simultaneously, commencing at the end of the panel remote from said headings, by establishing Working places simultaneously in pillars lying in a plurality of adjacent rows, and maintaining the line of robbing substantially normal tothe entries.

4. In a method of mining coal, the steps including driving a set of headings through a body of coal to be mined, turning a set of room entries 01T of said headings intermediate the sides of a panel lying on'one side. of said headings, driving said entries through substantially the full depth of the panel, turning rooms off of both sides of lsaid entries at angles of substantiallyy less than 90 to said entriesfadjacent the end of the panel remote from the headings, thereby leaving spaced rows of pillars extending on both sides of said entries at said angles thereto, robbing said pillars in retreat across the entire width of the panel'simultaneously, commencing at the end of the panel remote from said headings, by establishing working places simultaneously in pillars lyingV in a plurality of adjacent rows, and maintaining the line of robbing substantially normal to said entries.

SAMUEL M. CASSIDY. GEORGE M. RIGG. 

